Deep Insight on the Occurrence Feature of Iron Minerals in a Cyanide Leaching Residue and Its Effective Recovery with Magnetic Separation

Abstract

The occurrence features of ultrafine iron minerals in a cyanide leaching residue produced from a superlarge gold mining company in Yunnan Province were determined with chemical composition analysis, iron phase analysis, and mineral liberation analysis (MLA). The results show that the residue contains 26.74% iron, mainly occurring in the form of magnetite (26.33%) and limonite (69.41%), in which 67.40% magnetite and 73.00% limonite particles are fully liberated with particle sizes ranging from 9.6 µm to 75.0 µm. The rest are adjacent and wrapped intergrowths. Low-intensity magnetic separation and pulsating high-gradient magnetic separation were, respectively, proposed to recover magnetite and limonite from the residue, and under the optimized conditions, a high-grade magnetite concentrate assaying 64.05% Fe with 85.59% magnetite recovery and a qualified limonite concentrate assaying 50.94% Fe with 54.33% limonite recovery were, respectively, produced. The iron recovery for −30 µm fraction in the magnetite and limonite concentrates reached as high as 51.46%. It was found that the iron recovery for −30µm ultrafine fraction is lower than those of coarser fractions, as a result of the relatively enhanced hydrodynamic drag acting onto the particles, compared with the magnetic force. Entrainment occurs between the ultrafine iron minerals and gangues, thereby reducing the iron grade for the ultrafine fraction. This research outcome would provide a valuable reference for the economic and effective utilization of iron resources from such residues.

Mathematical Model of Ilmenite Separation Efficiency Using a High Gradient Plate Magnetic Separator

“…Raised baffles on the surface of the belt are distributed at equal intervals. The SPBC-0315 plate high gradient magnetic separator is used in this experiment, magnetic system length is a fixed value of 1 m, whose inclination angle is 5 • [17,18], and the separation experiment content includes rinsing water consumption and belt speed two factors on the separation performance. The rinsing water consumption is set to 9.5-29.9 L/min, and the belt speed is set to 2-6.5 r/min.…”

Application of High-Gradient Magnetic Separation for the Recovery of Super-Paramagnetic Polymer Adsorbent Used in Adsorption and Desorption Processes

“…In the past, magnetic separation (MS) was used for magnetic mineral separation in the metallurgical industry [1], the de-ironization of kaolin in the paper industry [2] and pyrite removal in the coal mining industry [3]. Recently, due to the use of magnetic particles as a carrier with the affinity ligand on the surface, MS technology has been widely applied in biochemistry [4], biomedical engineering [5][6][7] and environmental engineering, including protein purification [8], separation of lactoferrin [9], cell separation [10], immunoassay [11], enzyme immobilization [4], affinity separation [12][13][14][15][16] and waste water treatment [17][18][19][20][21][22][23][24]. MS uses a magnetic driving force to separate magnetic and non-magnetic materials.…”